Erratic motion and breakage of driving tapes for rapier heads on rapier looms has long been a problem resulting in damage to associated loom parts, ends down, excessive maintenance and down time. Such problems have been found upon stroboscopic examination to result from irregular flight paths on the return stroke of the rapiers. The mass of the rapier head causes flexing of the drive tapes with tendency of the remote end of the rapier heads to lift from the raceplate.
This problem becomes more acute at higher speeds and is, therefore, a limitation on loom speeds. It has been found, for example, that utilization of a magnet near the point of maximum flexing of the drive tapes can result in less breakage with increased loom speeds. The inertia force of the rapier head may thus be neutralized. It is believed that by utilizing the invention, 96 inch wide loom speeds may be increased from about 200 picks per minute to from about 230 to 250 picks per minute. Wide looms of 160 inches in width may be expected to operate at from about 180 to 190 picks per minute or more.
The prior art includes patents illustrating the use of magnets for guiding the flight of shuttles during weaving as for example, U.S. Letters Pat. Nos. 2,647,542 and 3,114,398. Patents utilizing magnets for facilitating transfer of yarn from one rapier head to another during weaving include U.S. Letters Pat. Nos. 3,438,402 and 3,957,089, whereas U.S. Letters Pat. No. 3,863,682 illustrates the use of sequentially operated magnets for propelling a shuttle along a race.